I'm curious if there is a software program that will allow me to highlight lyrics by simply singing over the mp3? I've heard the common space-bar and control key taps method is quite laborious. If the software could keep the highlight moving as long as I'm singing and stop when there is silence, this would make it much easier, I think. With some fine-tuning features after, and being able to save it off as an MP4 would be perfect.

I have hundreds of audio tracks that I need to make lyricized video tracks quickly. Any suggestions?

I'm afraid the old space-bar method is the only option available. If the method you described would work all you would need to do is hold down and release the space-bar. But you can't effectively synchronize the lyrics that way. You must tap the space-bar with the rhythm of the lyrics and the music.